Today I used GlassGiant.com for the first time. I didn't want to make just a simple hand-drawn sign, so I tried it out. GlassGiant allows you to create an image, like the one shown below, and allows you to save it to your computer. Once you create an image, right click on it and choose "save image as". To make my poster, I used MS Word, inserted my image, adjusted the size to fill a 8.5 x 11" piece of paper, and printed it.
If you'd rather embed your image to your class website or blog, you can create a free GlassGiant account. This allows you to save your images and provides the html code to embed your image directly into your site. The image above is saved by right-clicking, and the image below is embedded using html code. There's no difference. It isn't necessary to create an account, since images can be saved to your computer. Either way, GlassGiant is simple and easy to use. Give it a try!